Just how hot would it have to be outside for you to start heating up by degrees on the inside? Are we talking Southern Europe in the summer, saunas, or laying inside a furnace?

I was always under the impression that this statement was in reference to internally generated heat, like when running a fever. I'm curious now if this also covers situations like you inquire about, though I wonder why metabolic rate should be increased in those scenarios. Due the processes involved with the body's cooling mechanisms, perhaps?

I was always under the impression that this statement was in reference to internally generated heat, like when running a fever. I'm curious now if this also covers situations like you inquire about, though I wonder why metabolic rate should be increased in those scenarios. Due the processes involved with the body's cooling mechanisms, perhaps?

I was too for quite some time but heat exposure per se seems to induce it.

cold immersion for performance recovery is not as effective as cryotherapy. Cold shock proteins are triggered which releases 2 to 3 fold of norepinephrine. Also you trigger the RBM3 gene which helps the potential to regrow new synapses in the brain.